DMC-1000
Chapter 7 Application Programming
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105
Special Operands (Keywords)
The DMC-1000 provides a few operands which give access to internal variables that are not accessible
by standard DMC-1000 commands.
KEYWORD FUNCTION
_BGn
*Is equal to a 1 if motion on axis ‘n’ is complete, otherwise equal to 0.
_DA
*Is equal to the number of arrays available
_DL
*Is equal to the number of available labels for programming
_DM
*Is equal to the available array memory
_HMn
*Is equal to status of Home Switch (equals 0 or 1)
_LFn
Is equal to status of Forward Limit switch input of axis ‘n’ (equals 0 or 1)
_LRX
Is equal to status of Reverse Limit switch input of axis ‘n’ (equals 0 or 1)
_UL
*Is equal to the number of available variables
TIME
Free-Running Real Time Clock (off by 2.4% - Resets with power-on).
Note: TIME does not use an underscore character (_) as other keywords.
* - These keywords have corresponding commands while the keywords _LF, _LR, and TIME do not
have any associated commands. All keywords are listed in the Command Summary, Chapter 11.
Examples of Keywords
Instruction Interpretation
V1=_LFX
Assign V1 the logical state of the Forward Limit Switch on the X-axis
V3=TIME
Assign V3 the current value of the time clock
V4=_HMW
Assign V4 the logical state of the Home input on the W-axis
Arrays
For storing and collecting numerical data, the DMC-1000 provides array space for 1600 elements or
8000 elements for controllers with 5 or more axes, or with controller with the -MX option. The arrays
are one dimensional and up to 14 different arrays may be defined (30 for controllers with 5 or more
axes, or the -MX option). Each array element has a numeric range of 4 bytes of integer (2
31
)followed
by two bytes of fraction (+/-2,147,483,647.9999).
Arrays can be used to capture real-time data, such as position, torque and analog input values. In the
contouring mode, arrays are convenient for holding the points of a position trajectory in a record and
playback application.
Defining Arrays
An array is defined with the command DM. The user must specify a name and the number of entries
to be held in the array. An array name can contain up to eight characters, starting with an uppercase
alphabetic character. The number of entries in the defined array is enclosed in [ ].
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